Rheological performance of bitumen mixed with laboratory simulated polymerized RAP binders.

• Recycling of simulated Polymerized RAP produced using standard laboratory aging techniques. • Mix aging is better to simulate RAP from SBS PMB with 3 to 4% SBS. • Standard aging methods have distinct impact on performance of aged recycled PMB. Researchers have mostly used three artificial aging techniques, namely pressure aging vessel (PAV) binder aging, compacted mix aging (CMA), and loose mix aging (LMA) to simulate recycled asphalt pavement (RAP) binder in the laboratory. RAP binder (RAPB) simulated using different techniques will differ in characteristics and may affect the performance of the base binder differently. Which may affect the parameters used for blending and recycling, such as the selection of base binder, rejuvenator dosage, etc. Therefore, in this study, three RAP binders, namely RAPB-P, RAPB-C, and RAPB-L, were simulated from a polymer modified binder (PMB) with 3.5% SBS content, using PAV aging (100 °C, 20 hrs, 2.1 MPa), CMA (85 °C, 5 days) and LMA (85 °C, 8 days), respectively. These polymerized RAPBs were added to an unmodified binder (AC 30) at three proportions: 15 %, 25 %, and 40 %. These RAPB and AC 30 blends were characterized in terms of their dynamic viscosity, mixing and compaction temperature, and high temperature performance grade (PG). Superpave rutting factor (|G*|/sin δ) and multiple stress creep and recovery (MSCR) test parameters were used to evaluate the rutting performance of the RAPB blended AC 30 binders. Further, resistance to yielding and elastic recovery values were evaluated using the binder yield energy test (BYET). The test results suggested that all three RAP binders affect the performance of the AC 30 binder differently, which was also confirmed by statistical analysis using one-way ANOVA. From MSCR and BYET test results, it may be stated that RAP binder simulated from standard PAV aging may mislead in predicting the high and intermediate temperature performance of AC 30 binder with RAPB. Overall, the present study is helpful for asphalt researchers and practitioners to understand how the selection of different defined aging strategies affects the performance of aged recycled PMB with unmodified base binder. [ABSTRACT FROM AUTHOR]